Operating Pressure Research Articles

Research on the application of artificial intelligence tools to predict the operating temperature and pressure of the pipeline transportation system at the Hai Thach - Moc Tinh field

The observation of operating parameters for the single-phase or multi-phase flows of oil and gas pipelines always plays an important role and prerequisite in daily operation. The inlet and outlet parameters of the pipeline such as pressure and temperature will greatly affect the efficiency of the production and transportation process of fields. These parameters are very important. It must be required to observe carefully and strictly. In fact, pressure and temperature signal gauges will always be set up at the inlet and outlet of the pipeline for continuously variable transmission of the signal to the central control room, then the operator can observe regularly. Alarms will be triggered when the signal goes out of the setting operation area. However, the operational parameters transmitted from this gauge are only available after the actual fluid flow passes through the pipeline. This will limit when the operator needs to apply calculation methods to pre-predict the flow regime, and operating parameters of the fluid in the pipeline when fluid flows has not passed through the pipeline. From that approach, the paper presents the result of research on the application of machine learning algorithms (ML) to build models to predict operating conditions of three-phase flows in the pipeline at Hai Thach- Moc Tinh field based on input parameters such as the open of wellhead flow control valve of wells located in wellhead platform WHP-MT1, WHP-HT1, and the commercial gas volume. The results of the research show that the ML calculation method gives the result which is only +/-2 barg/20C difference compared to the field data obtained from pressure (HT1-PT-0911) and temperature (HT1-TI-0911) signals set up at the outlet of the transportation pipeline at the Hai Thach-Moc Tinh field.

Creep–fatigue life prediction of a titanium alloy deep-sea submersible using a continuum damage mechanics-informed BP neural network model

Deep-sea submersibles are subjected to trapezoidal wave loading during operation, which can cause creep–fatigue failure of pressure hull structures. To ensure structural safety, it is necessary to develop accurate and efficient creep–fatigue life prediction methods. This paper proposes a continuum damage mechanics-informed BPNN approach for predicting the creep–fatigue life of titanium alloy submersibles. To obtain a reliable sample set, the creep–fatigue life is calculated based on the titanium alloy room-temperature creep–fatigue damage model and numerical analysis methods proposed by the authors. The operating duration, operating pressure, axial stress, and circumferential stress were selected as the input variables, whereas the number of cycles and actual operating duration were chosen as the output variables. The proposed model fills the current gap of a lack of research on the creep‒fatigue life prediction of titanium alloy deep-sea submersibles via machine learning methods. The research results show that the neural network model established in this paper can quickly and accurately predict the creep–fatigue life of titanium alloy deep-sea submersibles. A sensitivity analysis of the input parameters revealed that the creep–fatigue life is more sensitive to the operational pressure than to the dwell time.

Assessment of sensor-based automatic smart watering unit for paddy nurseries under Indian perspective

A sensor-based automatic watering unit was developed to irrigate the paddy seedling trays. The watering unit comprised six flat spray nozzles with a direct current (DC) water pump and flow sensor, and these were kept at the top of the conveyor frame, which was actuated by a DC water pump with a solenoid valve to drop the water in trays. The actuation of the DC solenoid valve was controlled by a limit switch fitted to the conveyor frame, which sensed the moving trays on the conveyor. The performance of the developed unit was evaluated, and process optimization was performed using the Inscribed Central Composite Design in Response Surface Methodology. The effect of main operating parameters- chain conveyor speed (0.123, 0.196, and 0.27 m/s), spray operating pressure (1.5, 3.0, and 4.5 kg/cm2), and spray height (10,30 and 50 cm) on the performance of the sensor-based automatic watering unit was studied in terms of the amount of water spray requirement and coefficient of water spray uniformity in trays. The responses of the unit at its optimal parameter operation (spray operating pressure 4.5 kg/cm2, spray height 10 cm, and chain conveyor speed 0.14 m/s) were found to be 1.31 L/tray as the amount of water spray requirement and 92.41 % as the coefficient of water spray uniformity of the unit. Hence, it can be an efficient substitute with significantly less power consumption 41 W with a higher working capacity of 780 trays/h for watering into the paddy tray nursery. The developed sensor-based automatic smart watering unit saves irrigation water per square area of 68.90 %, 76.13 %, and 82.31 % compared to existing drip, sprinkler, and flood irrigation methods in mat-type paddy nurseries. The developed sensor-based automatic smart watering unit saves the watering cost INR 11,567.16 (140.02 USD) per hectare, reducing cost by 63.7 % compared to manual watering in the mat-type nursery preparation. Thus, an automatic smart watering unit in a paddy tray nursery offers consistent and uniform watering from an Indian perspective, promoting uniform germination, crop growth, and establishment. It conserves water by ensuring the right amount of water is applied at the right time, avoiding overwatering or under-watering.

Low-pressure high-current magnetron discharge with electron injection: From self-sputtering with multiply charged metal ions to non-sputtering with “pure” gas ions

We report our experimental investigations of the effect on the ion composition, including the ion mass-to-charge composition, of electron injection into the plasma of a high-current pulsed magnetron discharge in the ultra-low operating pressure range. We show that changing the magnetron discharge voltage by injecting additional electrons with adjustable current allows implementation of two operating modes: one with a plasma in which metal ions dominate (including multiply charged ions for certain target materials with low sputtering yield), and the other a magnetron non-sputtering mode with plasma of only gaseous ions.

Integrating 1D and 3D geomechanical modeling to ensure safe hydrogen storage in bedded salt caverns: A comprehensive case study in canning salt, Western Australia

The viability of hydrogen storage in bedded salt caverns hinges on understanding the geomechanical challenges posed by the anisotropic stress states and complex geology of such environments. This study presents a comprehensive geomechanical analysis focusing on a proposed cavern within the Carribuddy Formation in Western Australia, characterized by its interbedded salt layers. This paper introduces a new geomechanical workflow, encompassing 1D and 3D modeling techniques to provide detailed changes of mechanical properties and stress state in interbedded salt formation allowing to identify the initial optimal operational pressures for underground hydrogen storage. Initial 1D models evaluated mechanical properties and in-situ stresses, while subsequent 3D simulations, enriched by data from neighboring wells, detailed the stress, strain, and displacement responses of the cavern walls to internal pressure changes. The analysis pinpointed an initial safe gas pressure range between 3000 and 4000 psi, attributing this margin to the robust characterization of the mechanical and in-situ stress of the formation. Our findings underscore the significance of high-resolution geomechanical modeling in identifying initial optimal operational pressures for hydrogen storage in salt caverns, ensuring both safety and structural integrity.

Recovery of ammonia nitrogen from simulated reject water by bipolar membrane electrodialysis

ABSTRACT Ammonia monohydrate (NH3·H2O) is an important chemical widely used in industrial, agricultural, and pharmaceutical fields. Reject water is used as the raw material in self-built bipolar membrane electrodialysis (BMED) to produce NH3·H2O. The effects of electrode materials, membrane stack structure, and operating conditions (current density, initial concentrations of the reject water, and initial volume ratio) on the BMED process were investigated, and the economic costs were analyzed. The results showed that compared with graphite electrodes, ruthenium-iridium-titanium electrodes as electrode plates for BMED could increase current efficiency (25%) and reduce energy consumption (26%). Compared with two-compartment BMED, three-compartment BMED had a higher ammonia nitrogen conversion rate (86.6%) and lower energy consumption (3.5 kW· h/kg). Higher current density (15 mA/cm2) could achieve better current efficiency (79%). The BMED performances were improved when the initial NH 4 + concentrations of the reject water increased from 500 mg NH 4 + /L to 1000 mg NH 4 + /L, but the performance decreased as the concentration increased from 1000 mg NH 4 + /L to 1500 mg NH 4 + /L. High initial volume ratio of the salt compartment and product compartment was beneficial for reducing energy consumption. Under the optimal operating conditions, only 0.13 $/kg reject water was needed to eliminate the environmental impact of reject water accumulation. This work indicates that BMED can not only achieve desalination of reject water, but also generate products that alleviate the operational pressure of factories.

Peran Apron Movement Control (AMC) Dalam Menerapkan Kedisiplinan Kerja Karyawan Di Bandar Udara Internasional Sultan Hasanuddin Makassar

Air transportation is the primary choice due to its speed, safety, and comfort. Airports are places where aircraft land and take off and conduct various activities related to passengers and cargo, categorized into domestic and international. The Apron Movement Control (AMC) unit at PT Angkasa Pura I oversees movements in the apron area and provides services to airport users. Strict supervision is required to maintain safety and discipline on the apron. However, observations at the AMC at Sultan Hasanuddin International Airport in Makassar show a lack of discipline among staff, such as oil spills on the apron, which pose a safety hazard. This research aims to understand the role of AMC in enforcing employee discipline and the challenges faced at Sultan Hasanuddin International Airport in Makassar. This research employs a qualitative approach to understand the phenomena in the Apron Movement Control unit at PT Angkasa Pura I, Sultan Hasanuddin International Airport in Makassar, from June 1 to July 31, 2024. Primary data were collected through interviews and direct observations, while secondary data were obtained from company documents and literature studies. Data analysis involves reduction, presentation, and conclusion drawing, with data validity tested through source, technique, and time triangulation. Research steps include interviews, observations, data analysis, and conclusion drawing.The results show that the Apron Movement Control (AMC) unit at Sultan Hasanuddin International Airport in Makassar plays a crucial role in maintaining security, order, and discipline on the apron. They control the movements of aircraft, vehicles, and personnel and ensure operations follow safety procedures. AMC also acts as disciplinarian and educator through regular training. However, they face challenges such as a lack of employee understanding of procedures, limited communication equipment, communication challenges due to noise, and high operational pressure. To overcome these challenges, AMC needs to strengthen training, improve communication and coordination, enhance facilities, and increase employee welfare. These measures are expected to improve AMC's performance and instill a strong work discipline culture, making them the front line in maintaining airport security and operational efficiency.

A Review of the Utilization of CO2 as a Cushion Gas in Underground Natural Gas Storage

A cushion gas is an indispensable and the most expensive part of underground natural gas storage. Using CO2 injection to provide a cushion gas, not only can the investment in natural gas storage construction be reduced but the greenhouse effect can also be reduced. Currently, the related research about the mechanism and laws of CO2 as a cushion gas in gas storage is not sufficient. Consequently, the difference in the physical properties of CO2 and CH4, and the mixing factors between CO2 and natural gas, including the geological conditions and injection–production parameters, are comprehensively discussed. Additionally, the impact of CO2 as a cushion gas on the reservoir stability and gas storage capacity is also analyzed by comparing the current research findings. The difference in the viscosity, density, and compressibility factor between CO2 and CH4 ensures a low degree of mixing between CO2 and natural gas underground, thereby improving the recovery of CH4 in the operation process of gas storage. In the pressure range of 5 MPa–13 MPa and temperature range of 303.15 K–323.15 K, the density of CO2 increases five to eight times, while the density of natural gas only increases two to three times, and the viscosity of CO2 is more than 10 times that of CH4. The operation temperature and pressure in gas storage should be higher than the temperature and pressure in the supercritical conditions of CO2 because the diffusion ability between the gas molecules is increased in these conditions. However, the temperature and pressure have little effect on the mixing degree of CO2 and CH4 when the pressure is over the limited pressure of supercritical CO2. The CO2, with higher compressibility, can quickly replenish the energy of the gas storage facility and provide sufficient elastic energy during the natural gas production process. In addition, the physical properties of the reservoir also have a significant impact on the mixing and production of gases in gas storage facilities. The higher porosity reduces the migration speed of CO2 and CH4. However, the higher permeability promotes diffusion between gases, resulting in a higher degree of gas mixing. For a large inclination angle or thick reservoir structure, the mixed zone width of CO2 and CH4 is small under the action of gravity. An increase in the injection–production rate intensifies the mixing of CO2 and CH4. The injection of CO2 into reservoirs also induces the CO2–water–rock reactions, which improves the porosity and is beneficial in increasing the storage capacity of natural gas.

Reliable Detection of Chemical Warfare Agents Using High Kinetic Energy Ion Mobility Spectrometry.

High Kinetic Energy Ion Mobility Spectrometers (HiKE-IMS) ionize and separate ions at reduced pressures of 10-40 mbar and over a wide range of reduced electric field strengths E/N of up to 120 Td. Their reduced operating pressure is distinct from that of conventional drift tube ion mobility spectrometers that operate at ambient pressure for trace compound detection. High E/N can lead to a field-induced fragmentation pattern that provides more specific structural information about the analytes. In addition, operation at high E/N values adds the field dependence of ion mobility as an additional separation dimension to low-field ion mobility, making interfering compounds less likely to cause a false positive alarm. In this work, we study the chemical warfare agents tabun (GA), sarin (GB), soman (GD), cyclosarin (GF) and sulfur mustard (HD) in a HiKE-IMS at variable E/N in both the reaction and the drift region. The results show that varying E/N can lead to specific fragmentation patterns at high E/N values combined with molecular signals at low E/N. Compared to the operation at a single E/N value in the drift region, the variation of E/N in the drift region also provides the analyte-specific field dependence of ion mobility as additional information. The accumulated data establish a unique fingerprint for each analyte that allows for reliable detection of chemical warfare agents even in the presence of interfering compounds with similar low-field ion mobilities, thus reducing false positives.

Source characterization of a ducted source using acoustic free velocity

A common method to characterize linear time invariant ducted acoustic sources is the electro-acoustic analogy. The sources are typically defined by their internal source strength and source impedance. Various methods have emerged to determine the source characteristics, broadly categorized into direct and indirect methods. Direct methods involve using a secondary source with significantly higher amplitude to measure source impedance but cannot determine source strength. Indirect methods vary acoustic loads to obtain both source strength and source impedance, accuracy depends on appropriate load combinations. In this research, we propose an inverse method to determine the acoustic source strength from the measured acoustic transfer function and the operational acoustic pressure. This approach yields what we term as the "acoustic free velocity," corresponding to a plane monopole source that characterizes the original sound source. Subsequently, the source impedance is obtained using the acoustic free velocity in conjunction with the load impedance and acoustic pressure in the acoustic circuit. The method is demonstrated using a compressor driver source attached to a 1 3/8" impedance tube. Validation of the measured source strength and source impedance is conducted using a two-load method. Additionally, prediction of muffler insertion loss shows a good correlation with experimental measurements, affirming the efficacy of the proposed methodology.

Subcooled flow boiling characteristics and CHF in an eccentric annulus at low pressure conditions

Controlled flow boiling conditions enhance the heat transfer rate in various industrial applications such as heat exchangers, fuel rod bundles etc. In nuclear industry, the presence of mixing vanes, spacers, channel creep deformation etc., may lead to the formation of narrow and wide zones around the fuel rods. The asymmetry in the cross-sectional flow area around the fuel rod can be modelled as eccentricity which may cause an irregular coolant flow distribution affecting the heat transfer rate. In the present study, the eccentricity (e) is defined as the ratio of offset (s) to the difference in radii of inner and outer cylinders (Ro−Ri). The current study introduces a framework that involves calibrating the departure size of vapour bubble (D) in the EMF model framework which enables the accurate prediction of subcooled flow boiling characteristics and CHF power in an annulus (0.0≤e≤0.50) at low operating pressure conditions. The developed framework is validated with experimental data and a very good match is noticed. It is observed that eccentricity causes a decrease in coolant peak velocity magnitude by 12.8% in the narrow zone for e=0.50. In the subcooled region, the accumulation of vapour bubbles impedes further heat transfer to the liquid coolant, and thus the peak heated wall temperature (≈380.88K) is observed in the narrow zone for e=0.50. Eccentricity causes early coolant phase change which in turn results in early occurrence of CHF (q=522KWm−2) in the narrow zone of e=0.50. A quadratic relationship is also established to predict the CHF power in terms of eccentricity (e) within 5% variation.

Under-expanded jet and diffusion characteristics for small-hole leakage of hydrogen-blended natural gas in high-pressure pipelines

Hydrogen blending in natural gas pipelines is an economical method of hydrogen transportation, but it can increase explosion risks from leakages. Current leakage models struggle to capture under-expanded jet structures near leakage holes due to limited computational resources and cannot accurately describe explosion hazardous distances of subsequent diffusion. A two-stage model for simulating the leakage of hydrogen-blended natural gas (HBNG) pipelines is introduced, comprising jet and diffusion models. The source strength determined in the jet model serves as the inlet boundary condition for the subsequent diffusion model. The results show that considering the under-expanded jet structure can more accurately reflect the pressure fluctuation changes near the leakage hole, particularly at the location of the Mach disc, xm. The pressure at the 10xm section of the jet region stabilizes at atmospheric pressure and utilizing this value as the inlet boundary for the diffusion model prevents supersonic and oscillatory regions. Subsequently, the impact of pipeline operating pressure, leakage hole diameter, and hydrogen blending ratio (HBR) on the far-field diffusion characteristics is analyzed. Notably, the leakage hole diameter has a more pronounced effect on the explosion hazardous distance compared to other factors. This research provides insights for the prevention and management of HBNG leakage accidents.

Modelling ultrasonic cavitation onset in spiral-wound reverse osmosis modules

A model was developed to predict the onset of inertial cavitation within a spiral-wound reverse osmosis module sonicated along its axis from within its pressure vessel. The aim was to investigate the scalability of ultrasonic antifouling for reverse osmosis applications. The model employs a one-dimensional discretization to represent the module feed channel, calculating each element's pressure, flow rate, permeate flux, and sonication intensity. The Blake threshold assesses whether the pressure amplitude at each element is sufficient to produce inertial cavitation. When applied with parameters from a typical small-scale reverse osmosis module, the model identified a linear relationship between inlet pressure and inertial cavitation onset location, with a constant inlet flow rate and sonication power. With a sonication power of 120 W and a flow rate of 8.796 × 10−5 m3 s−1, the model predicted that inertial cavitation could be induced throughout the reverse osmosis module with inlet pressures ranging from 335 kPa to 355 kPa. While these pressures may be inefficient from a permeate production standpoint compared to standard operating pressure, they could be produced temporarily as part of a regular membrane cleaning operation. The model estimates the system's power consumption during cleaning to be 134.8 W, approximately equal to the estimated system energy requirements under recommended operating conditions of 134.3 W. This suggests that this technology could integrate effectively with existing reverse osmosis systems.

Ramp-up in the air: Impairing or repairing aviation crews’ working conditions? A mixed-methods survey study on working conditions, health, and safety among cabin crew and pilots in Europe

IntroductionOrganizational changes, such as downsizing, can have profound implications for organizations, working conditions, and individual well-being. Similarly, rapid expansion also carries potential risks to individual health. During the Covid-19 pandemic, airlines experienced substantial organizational changes, such as downsizing and furloughs, followed by rapid expansion during the ramp-up phase of flying, posing risks to the health and safety of aviation personnel in the new post-pandemic aviation landscape. MethodThis cross-sectional and mixed-method survey study aimed to identify what post-pandemic challenges pilots (N = 6379) and cabin crew (N = 2679) face regarding working conditions, health, and flight safety. ResultsThe results indicate deteriorated working conditions, health, and perceived safety among crew in the new aviation landscape. One in two cabin crew and one in three pilots report a decline in mental health. Whilst most pilots and cabin crew report no change in overall safety, 29% of cabin crew and 36% of surveyed pilots state that safety has deteriorated since the onset of the pandemic. This development is connected to an increased sense of industry instability, job insecurity, imbalanced job design, and management distrust among aviation crew. Furthermore, the uncertainties surrounding the industry have not only impacted job security and induced job-related worry but have also intensified operational pressures, with perceived impacts on flight and passenger safety. ConclusionThe organizational framework, e.g., financial pressures, may have an effect on safety, either directly or indirectly by financial worry impeding crew performance. Hence, safety cannot be examined in isolation from employee health but must be understood in relation to the complex dynamics and competing objectives within aviation. Further, crew experiences across Europe are largely homogeneous, suggesting that identified risks may not be airline specific. Therefore, it is important to further examine the industry framework for inherent risk factors that could impact employee health and flight safety.

Performance pressure and annual report text manipulation: Evidence from China

AbstractBuilding on attribution theory, this study investigates the antecedents of corporate annual report text manipulation from the perspective of managerial performance pressure. Using a data set comprising 15,076 samples from companies listed on China's Shanghai and Shenzhen A‐share markets between 2009 and 2021, we reveal that as management faces performance pressure, they tend to increase content about external environmental risk and policy uncertainty in annual reports due to actor–observer bias. When incorporating Confucian cultural factors into the research framework, the study found that the strength of Confucian culture mitigates the correlation between the pressure of management performance and annual report manipulation. However, the level of marketization where a corporation is located can undermine the ethical norms upheld by Confucian culture. In additional analysis, we also discovered that the longer the duration of performance pressure, the greater the extent of manipulation within the annual reports initiated by the management. Interestingly, the social performance pressure generated from ESG performance also positively influences annual report textual manipulation, compared to operational performance pressure. This study explores the impact of management performance pressure on information disclosure decisions from the perspective of performance attribution, not only extending the boundaries of attribution theory but also providing guidance for policymakers to enhance the supervision of annual report disclosures and for capital market investors to optimize investment decisions.

Experimental investigation of camless air engine to improve performance by the novel controller and exhaust pressure predicting technique

In the face of the climate crisis, hike in prices of petroleum products, and limited gasoline sources, it is imperative to explore the possible opportunities in the field of energy transformation technology. Non-conventional and non-hazardous green fuel-air engine technology has proven to have a promising future in propulsion technology. In the air engine, the camless mechanism has created scope for research by replacement option of cam-follower with variable valve train (solenoid valve), which can be controlled electronically. In this paper, work is done on the operational parameters (i.e., cycle time, flow rate, and crank position) of camless air engines and proposed a controlling mechanism with experimental results to improve the system's efficiency. Control of intake duration maximizes the utilization of input compressed air power by allowing the optimum amount of air to expand fully. The novel controller was designed, developed, and tested, which controls the engine intake duration by estimating exhaust pressure. A prototype model was built with an electronic control circuit and pneumatic system, which records signals of operational parameters with the help of feedback sensors and controls the engine's intake duration at different operating pressure ranging from 3 to 6.5 bar. Experiments were conducted, and the results of two cycles were compared, case-I, where compressed air is continuously supplied from 0° to 170° of crank angle, and case-II controlled cycle, which controls intake duration by estimating exhaust pressure. Results show the average efficiency improvement of 11.91 % in case-II compared to case-I and also improvement in work done and RPM (Revolution per Minute) of the cycle. Thus, the control system in a camless air engine increases the feasibility of the air engine as one of the propulsion technologies in a city vehicle and even in the Compressed Air Energy Storage System (CAES).

A Reliability Assessment Method for Natural Gas Pipelines with Corroded Defects That Considers Detection Cycles

With the development of natural gas pipelines, the proportion of aged pipelines in service has been increasing, and corrosion remains a primary cause of pipeline failure. Regular inspections and reliability assessments are crucial to ensure the safe operation of pipelines. This study investigated an efficient reliability assessment method for corroded pipelines that considers in-line inspection intervals. First, this study compared the commonly used limit state equations for corrosion defects to select one suitable for X80-grade steel pipelines. Additionally, a Tail-Fit Monte Carlo Simulation (TF-MCS) algorithm was proposed to improve the computational speed by 30 times compared to traditional Monte Carlo simulations. Then, this study explored the inspection intervals used for reliability assessments of corroded pipelines. Finally, the parameter sensitivity was analyzed considering the yield strength, maximum operating pressure, and pipe diameter. This study ensures the reliable operation of corroded gas pipelines.

The Effects of Stress and Fatigue on Levels of Anxiety in Pilots: An Aviation Industry Sample

This study aims to provide a comprehensive understanding of the impact of stress and fatigue on pilots’ well-being, with a focus on anxiety. A quantitative research design utilizing structured questionnaires was employed to gather subjective reports from a sample of sixty airline pilots in the commercial aviation industry. Stressors such as demanding flight schedules and operational pressure significantly contributed to increased anxiety levels among pilots. Secondly, fatigue resulting from irregular work hours and long flights emerged as a prominent factor influencing anxiety. Lastly, organizational factors such as lack of support systems and limited access to mental health resources were identified as additional contributors to heightened anxiety levels among pilots.

Effects of Valve, Armature, and Armature Pin Guidance on Diesel Injector Performance

The valve, armature, and armature pin are critical factors influencing the hydraulic pressure differences in diesel injectors, and are essential for injection and backflow quantity control. These components play crucial roles in enhancing energy efficiency and reducing engine emissions. This experimental study investigated the effects of clearance between the valve, armature, and armature pin guidance. Forty-nine 2000 bar common-rail injectors (Bosch) were tested in calibrated stations. Injection quantities were assessed at both minimum and maximum operational pressures. Backflow rates were specifically examined at maximum pressure. A correlation matrix was created using Python to analyze the relationship between inputs and outputs, identifying dominant characteristics that define injector behavior. Increased injector precision correlated with reduced fuel consumption and enhanced energy efficiency. The study found that the effect of clearance between the armature and armature pins was more significant than that between the valve and armature. Injection quantities were observed to increase with pressure, and no critical difference in injection quantities was noted among different diameter groups at the minimum pressure point. Backflow quantities were consistent within groups when the armature–armature pin and valve–armature clearances were minimized.

Extending the Operating Pressure Range of a Forevacuum-Pressure Plasma-Cathode Ribbon Electron Beam Source

Extending the Operating Pressure Range of a Forevacuum-Pressure Plasma-Cathode Ribbon Electron Beam Source